1 // SPDX-License-Identifier: GPL-2.0-only
3 * AMD Cryptographic Coprocessor (CCP) driver
5 * Copyright (C) 2013,2017 Advanced Micro Devices, Inc.
7 * Author: Tom Lendacky <thomas.lendacky@amd.com>
8 * Author: Gary R Hook <gary.hook@amd.com>
11 #include <linux/kernel.h>
12 #include <linux/kthread.h>
13 #include <linux/sched.h>
14 #include <linux/interrupt.h>
15 #include <linux/spinlock.h>
16 #include <linux/spinlock_types.h>
17 #include <linux/types.h>
18 #include <linux/mutex.h>
19 #include <linux/delay.h>
20 #include <linux/hw_random.h>
21 #include <linux/cpu.h>
23 #include <asm/cpu_device_id.h>
25 #include <linux/ccp.h>
29 struct ccp_tasklet_data {
30 struct completion completion;
34 /* Human-readable error strings */
35 static char *ccp_error_codes[] = {
37 "ERR 01: ILLEGAL_ENGINE",
38 "ERR 02: ILLEGAL_KEY_ID",
39 "ERR 03: ILLEGAL_FUNCTION_TYPE",
40 "ERR 04: ILLEGAL_FUNCTION_MODE",
41 "ERR 05: ILLEGAL_FUNCTION_ENCRYPT",
42 "ERR 06: ILLEGAL_FUNCTION_SIZE",
43 "ERR 07: Zlib_MISSING_INIT_EOM",
44 "ERR 08: ILLEGAL_FUNCTION_RSVD",
45 "ERR 09: ILLEGAL_BUFFER_LENGTH",
47 "ERR 11: ILLEGAL_MEM_ADDR",
48 "ERR 12: ILLEGAL_MEM_SEL",
49 "ERR 13: ILLEGAL_CONTEXT_ID",
50 "ERR 14: ILLEGAL_KEY_ADDR",
51 "ERR 15: 0xF Reserved",
52 "ERR 16: Zlib_ILLEGAL_MULTI_QUEUE",
53 "ERR 17: Zlib_ILLEGAL_JOBID_CHANGE",
54 "ERR 18: CMD_TIMEOUT",
55 "ERR 19: IDMA0_AXI_SLVERR",
56 "ERR 20: IDMA0_AXI_DECERR",
57 "ERR 21: 0x15 Reserved",
58 "ERR 22: IDMA1_AXI_SLAVE_FAULT",
59 "ERR 23: IDMA1_AIXI_DECERR",
60 "ERR 24: 0x18 Reserved",
61 "ERR 25: ZLIBVHB_AXI_SLVERR",
62 "ERR 26: ZLIBVHB_AXI_DECERR",
63 "ERR 27: 0x1B Reserved",
64 "ERR 27: ZLIB_UNEXPECTED_EOM",
65 "ERR 27: ZLIB_EXTRA_DATA",
67 "ERR 31: ZLIB_UNDEFINED_SYMBOL",
68 "ERR 32: ZLIB_UNDEFINED_DISTANCE_S",
69 "ERR 33: ZLIB_CODE_LENGTH_SYMBOL",
70 "ERR 34: ZLIB _VHB_ILLEGAL_FETCH",
71 "ERR 35: ZLIB_UNCOMPRESSED_LEN",
72 "ERR 36: ZLIB_LIMIT_REACHED",
73 "ERR 37: ZLIB_CHECKSUM_MISMATCH0",
74 "ERR 38: ODMA0_AXI_SLVERR",
75 "ERR 39: ODMA0_AXI_DECERR",
76 "ERR 40: 0x28 Reserved",
77 "ERR 41: ODMA1_AXI_SLVERR",
78 "ERR 42: ODMA1_AXI_DECERR",
79 "ERR 43: LSB_PARITY_ERR",
82 void ccp_log_error(struct ccp_device *d, int e)
84 dev_err(d->dev, "CCP error: %s (0x%x)\n", ccp_error_codes[e], e);
87 /* List of CCPs, CCP count, read-write access lock, and access functions
89 * Lock structure: get ccp_unit_lock for reading whenever we need to
90 * examine the CCP list. While holding it for reading we can acquire
91 * the RR lock to update the round-robin next-CCP pointer. The unit lock
92 * must be acquired before the RR lock.
94 * If the unit-lock is acquired for writing, we have total control over
95 * the list, so there's no value in getting the RR lock.
97 static DEFINE_RWLOCK(ccp_unit_lock);
98 static LIST_HEAD(ccp_units);
100 /* Round-robin counter */
101 static DEFINE_SPINLOCK(ccp_rr_lock);
102 static struct ccp_device *ccp_rr;
105 * ccp_add_device - add a CCP device to the list
107 * @ccp: ccp_device struct pointer
109 * Put this CCP on the unit list, which makes it available
112 * Returns zero if a CCP device is present, -ENODEV otherwise.
114 void ccp_add_device(struct ccp_device *ccp)
118 write_lock_irqsave(&ccp_unit_lock, flags);
119 list_add_tail(&ccp->entry, &ccp_units);
121 /* We already have the list lock (we're first) so this
122 * pointer can't change on us. Set its initial value.
125 write_unlock_irqrestore(&ccp_unit_lock, flags);
129 * ccp_del_device - remove a CCP device from the list
131 * @ccp: ccp_device struct pointer
133 * Remove this unit from the list of devices. If the next device
134 * up for use is this one, adjust the pointer. If this is the last
135 * device, NULL the pointer.
137 void ccp_del_device(struct ccp_device *ccp)
141 write_lock_irqsave(&ccp_unit_lock, flags);
143 /* ccp_unit_lock is read/write; any read access
144 * will be suspended while we make changes to the
145 * list and RR pointer.
147 if (list_is_last(&ccp_rr->entry, &ccp_units))
148 ccp_rr = list_first_entry(&ccp_units, struct ccp_device,
151 ccp_rr = list_next_entry(ccp_rr, entry);
153 list_del(&ccp->entry);
154 if (list_empty(&ccp_units))
156 write_unlock_irqrestore(&ccp_unit_lock, flags);
161 int ccp_register_rng(struct ccp_device *ccp)
165 dev_dbg(ccp->dev, "Registering RNG...\n");
166 /* Register an RNG */
167 ccp->hwrng.name = ccp->rngname;
168 ccp->hwrng.read = ccp_trng_read;
169 ret = hwrng_register(&ccp->hwrng);
171 dev_err(ccp->dev, "error registering hwrng (%d)\n", ret);
176 void ccp_unregister_rng(struct ccp_device *ccp)
179 hwrng_unregister(&ccp->hwrng);
182 static struct ccp_device *ccp_get_device(void)
185 struct ccp_device *dp = NULL;
187 /* We round-robin through the unit list.
188 * The (ccp_rr) pointer refers to the next unit to use.
190 read_lock_irqsave(&ccp_unit_lock, flags);
191 if (!list_empty(&ccp_units)) {
192 spin_lock(&ccp_rr_lock);
194 if (list_is_last(&ccp_rr->entry, &ccp_units))
195 ccp_rr = list_first_entry(&ccp_units, struct ccp_device,
198 ccp_rr = list_next_entry(ccp_rr, entry);
199 spin_unlock(&ccp_rr_lock);
201 read_unlock_irqrestore(&ccp_unit_lock, flags);
207 * ccp_present - check if a CCP device is present
209 * Returns zero if a CCP device is present, -ENODEV otherwise.
211 int ccp_present(void)
216 read_lock_irqsave(&ccp_unit_lock, flags);
217 ret = list_empty(&ccp_units);
218 read_unlock_irqrestore(&ccp_unit_lock, flags);
220 return ret ? -ENODEV : 0;
222 EXPORT_SYMBOL_GPL(ccp_present);
225 * ccp_version - get the version of the CCP device
227 * Returns the version from the first unit on the list;
228 * otherwise a zero if no CCP device is present
230 unsigned int ccp_version(void)
232 struct ccp_device *dp;
236 read_lock_irqsave(&ccp_unit_lock, flags);
237 if (!list_empty(&ccp_units)) {
238 dp = list_first_entry(&ccp_units, struct ccp_device, entry);
239 ret = dp->vdata->version;
241 read_unlock_irqrestore(&ccp_unit_lock, flags);
245 EXPORT_SYMBOL_GPL(ccp_version);
248 * ccp_enqueue_cmd - queue an operation for processing by the CCP
250 * @cmd: ccp_cmd struct to be processed
252 * Queue a cmd to be processed by the CCP. If queueing the cmd
253 * would exceed the defined length of the cmd queue the cmd will
254 * only be queued if the CCP_CMD_MAY_BACKLOG flag is set and will
255 * result in a return code of -EBUSY.
257 * The callback routine specified in the ccp_cmd struct will be
258 * called to notify the caller of completion (if the cmd was not
259 * backlogged) or advancement out of the backlog. If the cmd has
260 * advanced out of the backlog the "err" value of the callback
261 * will be -EINPROGRESS. Any other "err" value during callback is
262 * the result of the operation.
264 * The cmd has been successfully queued if:
265 * the return code is -EINPROGRESS or
266 * the return code is -EBUSY and CCP_CMD_MAY_BACKLOG flag is set
268 int ccp_enqueue_cmd(struct ccp_cmd *cmd)
270 struct ccp_device *ccp;
275 /* Some commands might need to be sent to a specific device */
276 ccp = cmd->ccp ? cmd->ccp : ccp_get_device();
281 /* Caller must supply a callback routine */
287 spin_lock_irqsave(&ccp->cmd_lock, flags);
289 i = ccp->cmd_q_count;
291 if (ccp->cmd_count >= MAX_CMD_QLEN) {
292 if (cmd->flags & CCP_CMD_MAY_BACKLOG) {
294 list_add_tail(&cmd->entry, &ccp->backlog);
301 list_add_tail(&cmd->entry, &ccp->cmd);
303 /* Find an idle queue */
304 if (!ccp->suspending) {
305 for (i = 0; i < ccp->cmd_q_count; i++) {
306 if (ccp->cmd_q[i].active)
314 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
316 /* If we found an idle queue, wake it up */
317 if (i < ccp->cmd_q_count)
318 wake_up_process(ccp->cmd_q[i].kthread);
322 EXPORT_SYMBOL_GPL(ccp_enqueue_cmd);
324 static void ccp_do_cmd_backlog(struct work_struct *work)
326 struct ccp_cmd *cmd = container_of(work, struct ccp_cmd, work);
327 struct ccp_device *ccp = cmd->ccp;
331 cmd->callback(cmd->data, -EINPROGRESS);
333 spin_lock_irqsave(&ccp->cmd_lock, flags);
336 list_add_tail(&cmd->entry, &ccp->cmd);
338 /* Find an idle queue */
339 for (i = 0; i < ccp->cmd_q_count; i++) {
340 if (ccp->cmd_q[i].active)
346 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
348 /* If we found an idle queue, wake it up */
349 if (i < ccp->cmd_q_count)
350 wake_up_process(ccp->cmd_q[i].kthread);
353 static struct ccp_cmd *ccp_dequeue_cmd(struct ccp_cmd_queue *cmd_q)
355 struct ccp_device *ccp = cmd_q->ccp;
356 struct ccp_cmd *cmd = NULL;
357 struct ccp_cmd *backlog = NULL;
360 spin_lock_irqsave(&ccp->cmd_lock, flags);
364 if (ccp->suspending) {
365 cmd_q->suspended = 1;
367 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
368 wake_up_interruptible(&ccp->suspend_queue);
373 if (ccp->cmd_count) {
376 cmd = list_first_entry(&ccp->cmd, struct ccp_cmd, entry);
377 list_del(&cmd->entry);
382 if (!list_empty(&ccp->backlog)) {
383 backlog = list_first_entry(&ccp->backlog, struct ccp_cmd,
385 list_del(&backlog->entry);
388 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
391 INIT_WORK(&backlog->work, ccp_do_cmd_backlog);
392 schedule_work(&backlog->work);
398 static void ccp_do_cmd_complete(unsigned long data)
400 struct ccp_tasklet_data *tdata = (struct ccp_tasklet_data *)data;
401 struct ccp_cmd *cmd = tdata->cmd;
403 cmd->callback(cmd->data, cmd->ret);
405 complete(&tdata->completion);
409 * ccp_cmd_queue_thread - create a kernel thread to manage a CCP queue
411 * @data: thread-specific data
413 int ccp_cmd_queue_thread(void *data)
415 struct ccp_cmd_queue *cmd_q = (struct ccp_cmd_queue *)data;
417 struct ccp_tasklet_data tdata;
418 struct tasklet_struct tasklet;
420 tasklet_init(&tasklet, ccp_do_cmd_complete, (unsigned long)&tdata);
422 set_current_state(TASK_INTERRUPTIBLE);
423 while (!kthread_should_stop()) {
426 set_current_state(TASK_INTERRUPTIBLE);
428 cmd = ccp_dequeue_cmd(cmd_q);
432 __set_current_state(TASK_RUNNING);
434 /* Execute the command */
435 cmd->ret = ccp_run_cmd(cmd_q, cmd);
437 /* Schedule the completion callback */
439 init_completion(&tdata.completion);
440 tasklet_schedule(&tasklet);
441 wait_for_completion(&tdata.completion);
444 __set_current_state(TASK_RUNNING);
450 * ccp_alloc_struct - allocate and initialize the ccp_device struct
452 * @dev: device struct of the CCP
454 struct ccp_device *ccp_alloc_struct(struct sp_device *sp)
456 struct device *dev = sp->dev;
457 struct ccp_device *ccp;
459 ccp = devm_kzalloc(dev, sizeof(*ccp), GFP_KERNEL);
464 ccp->axcache = sp->axcache;
466 INIT_LIST_HEAD(&ccp->cmd);
467 INIT_LIST_HEAD(&ccp->backlog);
469 spin_lock_init(&ccp->cmd_lock);
470 mutex_init(&ccp->req_mutex);
471 mutex_init(&ccp->sb_mutex);
472 ccp->sb_count = KSB_COUNT;
475 /* Initialize the wait queues */
476 init_waitqueue_head(&ccp->sb_queue);
477 init_waitqueue_head(&ccp->suspend_queue);
479 snprintf(ccp->name, MAX_CCP_NAME_LEN, "ccp-%u", sp->ord);
480 snprintf(ccp->rngname, MAX_CCP_NAME_LEN, "ccp-%u-rng", sp->ord);
485 int ccp_trng_read(struct hwrng *rng, void *data, size_t max, bool wait)
487 struct ccp_device *ccp = container_of(rng, struct ccp_device, hwrng);
489 int len = min_t(int, sizeof(trng_value), max);
491 /* Locking is provided by the caller so we can update device
492 * hwrng-related fields safely
494 trng_value = ioread32(ccp->io_regs + TRNG_OUT_REG);
496 /* Zero is returned if not data is available or if a
497 * bad-entropy error is present. Assume an error if
498 * we exceed TRNG_RETRIES reads of zero.
500 if (ccp->hwrng_retries++ > TRNG_RETRIES)
506 /* Reset the counter and save the rng value */
507 ccp->hwrng_retries = 0;
508 memcpy(data, &trng_value, len);
514 bool ccp_queues_suspended(struct ccp_device *ccp)
516 unsigned int suspended = 0;
520 spin_lock_irqsave(&ccp->cmd_lock, flags);
522 for (i = 0; i < ccp->cmd_q_count; i++)
523 if (ccp->cmd_q[i].suspended)
526 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
528 return ccp->cmd_q_count == suspended;
531 int ccp_dev_suspend(struct sp_device *sp, pm_message_t state)
533 struct ccp_device *ccp = sp->ccp_data;
537 spin_lock_irqsave(&ccp->cmd_lock, flags);
541 /* Wake all the queue kthreads to prepare for suspend */
542 for (i = 0; i < ccp->cmd_q_count; i++)
543 wake_up_process(ccp->cmd_q[i].kthread);
545 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
547 /* Wait for all queue kthreads to say they're done */
548 while (!ccp_queues_suspended(ccp))
549 wait_event_interruptible(ccp->suspend_queue,
550 ccp_queues_suspended(ccp));
555 int ccp_dev_resume(struct sp_device *sp)
557 struct ccp_device *ccp = sp->ccp_data;
561 spin_lock_irqsave(&ccp->cmd_lock, flags);
565 /* Wake up all the kthreads */
566 for (i = 0; i < ccp->cmd_q_count; i++) {
567 ccp->cmd_q[i].suspended = 0;
568 wake_up_process(ccp->cmd_q[i].kthread);
571 spin_unlock_irqrestore(&ccp->cmd_lock, flags);
577 int ccp_dev_init(struct sp_device *sp)
579 struct device *dev = sp->dev;
580 struct ccp_device *ccp;
584 ccp = ccp_alloc_struct(sp);
589 ccp->vdata = (struct ccp_vdata *)sp->dev_vdata->ccp_vdata;
590 if (!ccp->vdata || !ccp->vdata->version) {
592 dev_err(dev, "missing driver data\n");
596 ccp->use_tasklet = sp->use_tasklet;
598 ccp->io_regs = sp->io_map + ccp->vdata->offset;
599 if (ccp->vdata->setup)
600 ccp->vdata->setup(ccp);
602 ret = ccp->vdata->perform->init(ccp);
606 dev_notice(dev, "ccp enabled\n");
613 dev_notice(dev, "ccp initialization failed\n");
618 void ccp_dev_destroy(struct sp_device *sp)
620 struct ccp_device *ccp = sp->ccp_data;
625 ccp->vdata->perform->destroy(ccp);